xref: /qemu/block/qcow2.c (revision 1c46efaa0a175e468772405385ca26a1e35dd94c)
1585f8587Sbellard /*
2585f8587Sbellard  * Block driver for the QCOW version 2 format
3585f8587Sbellard  *
4585f8587Sbellard  * Copyright (c) 2004-2006 Fabrice Bellard
5585f8587Sbellard  *
6585f8587Sbellard  * Permission is hereby granted, free of charge, to any person obtaining a copy
7585f8587Sbellard  * of this software and associated documentation files (the "Software"), to deal
8585f8587Sbellard  * in the Software without restriction, including without limitation the rights
9585f8587Sbellard  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10585f8587Sbellard  * copies of the Software, and to permit persons to whom the Software is
11585f8587Sbellard  * furnished to do so, subject to the following conditions:
12585f8587Sbellard  *
13585f8587Sbellard  * The above copyright notice and this permission notice shall be included in
14585f8587Sbellard  * all copies or substantial portions of the Software.
15585f8587Sbellard  *
16585f8587Sbellard  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17585f8587Sbellard  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18585f8587Sbellard  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19585f8587Sbellard  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20585f8587Sbellard  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21585f8587Sbellard  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22585f8587Sbellard  * THE SOFTWARE.
23585f8587Sbellard  */
24faf07963Spbrook #include "qemu-common.h"
25585f8587Sbellard #include "block_int.h"
265efa9d5aSAnthony Liguori #include "module.h"
27585f8587Sbellard #include <zlib.h>
28585f8587Sbellard #include "aes.h"
29f7d0fe02SKevin Wolf #include "block/qcow2.h"
30585f8587Sbellard 
31585f8587Sbellard /*
32585f8587Sbellard   Differences with QCOW:
33585f8587Sbellard 
34585f8587Sbellard   - Support for multiple incremental snapshots.
35585f8587Sbellard   - Memory management by reference counts.
36585f8587Sbellard   - Clusters which have a reference count of one have the bit
37585f8587Sbellard     QCOW_OFLAG_COPIED to optimize write performance.
38585f8587Sbellard   - Size of compressed clusters is stored in sectors to reduce bit usage
39585f8587Sbellard     in the cluster offsets.
40585f8587Sbellard   - Support for storing additional data (such as the VM state) in the
41585f8587Sbellard     snapshots.
42585f8587Sbellard   - If a backing store is used, the cluster size is not constrained
43585f8587Sbellard     (could be backported to QCOW).
44585f8587Sbellard   - L2 tables have always a size of one cluster.
45585f8587Sbellard */
46585f8587Sbellard 
479b80ddf3Saliguori 
489b80ddf3Saliguori typedef struct {
499b80ddf3Saliguori     uint32_t magic;
509b80ddf3Saliguori     uint32_t len;
519b80ddf3Saliguori } QCowExtension;
529b80ddf3Saliguori #define  QCOW_EXT_MAGIC_END 0
53f965509cSaliguori #define  QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
549b80ddf3Saliguori 
55585f8587Sbellard static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
56585f8587Sbellard {
57585f8587Sbellard     const QCowHeader *cow_header = (const void *)buf;
58585f8587Sbellard 
59585f8587Sbellard     if (buf_size >= sizeof(QCowHeader) &&
60585f8587Sbellard         be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
61585f8587Sbellard         be32_to_cpu(cow_header->version) == QCOW_VERSION)
62585f8587Sbellard         return 100;
63585f8587Sbellard     else
64585f8587Sbellard         return 0;
65585f8587Sbellard }
66585f8587Sbellard 
679b80ddf3Saliguori 
689b80ddf3Saliguori /*
699b80ddf3Saliguori  * read qcow2 extension and fill bs
709b80ddf3Saliguori  * start reading from start_offset
719b80ddf3Saliguori  * finish reading upon magic of value 0 or when end_offset reached
729b80ddf3Saliguori  * unknown magic is skipped (future extension this version knows nothing about)
739b80ddf3Saliguori  * return 0 upon success, non-0 otherwise
749b80ddf3Saliguori  */
759b80ddf3Saliguori static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
769b80ddf3Saliguori                                 uint64_t end_offset)
779b80ddf3Saliguori {
789b80ddf3Saliguori     QCowExtension ext;
799b80ddf3Saliguori     uint64_t offset;
809b80ddf3Saliguori 
819b80ddf3Saliguori #ifdef DEBUG_EXT
829b80ddf3Saliguori     printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
839b80ddf3Saliguori #endif
849b80ddf3Saliguori     offset = start_offset;
859b80ddf3Saliguori     while (offset < end_offset) {
869b80ddf3Saliguori 
879b80ddf3Saliguori #ifdef DEBUG_EXT
889b80ddf3Saliguori         /* Sanity check */
899b80ddf3Saliguori         if (offset > s->cluster_size)
909b80ddf3Saliguori             printf("qcow_handle_extension: suspicious offset %lu\n", offset);
919b80ddf3Saliguori 
929b80ddf3Saliguori         printf("attemting to read extended header in offset %lu\n", offset);
939b80ddf3Saliguori #endif
949b80ddf3Saliguori 
9566f82ceeSKevin Wolf         if (bdrv_pread(bs->file, offset, &ext, sizeof(ext)) != sizeof(ext)) {
960bfcd599SBlue Swirl             fprintf(stderr, "qcow_handle_extension: ERROR: "
970bfcd599SBlue Swirl                     "pread fail from offset %" PRIu64 "\n",
980bfcd599SBlue Swirl                     offset);
999b80ddf3Saliguori             return 1;
1009b80ddf3Saliguori         }
1019b80ddf3Saliguori         be32_to_cpus(&ext.magic);
1029b80ddf3Saliguori         be32_to_cpus(&ext.len);
1039b80ddf3Saliguori         offset += sizeof(ext);
1049b80ddf3Saliguori #ifdef DEBUG_EXT
1059b80ddf3Saliguori         printf("ext.magic = 0x%x\n", ext.magic);
1069b80ddf3Saliguori #endif
1079b80ddf3Saliguori         switch (ext.magic) {
1089b80ddf3Saliguori         case QCOW_EXT_MAGIC_END:
1099b80ddf3Saliguori             return 0;
110f965509cSaliguori 
111f965509cSaliguori         case QCOW_EXT_MAGIC_BACKING_FORMAT:
112f965509cSaliguori             if (ext.len >= sizeof(bs->backing_format)) {
113f965509cSaliguori                 fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
1144c978075Saliguori                         " (>=%zu)\n",
115f965509cSaliguori                         ext.len, sizeof(bs->backing_format));
116f965509cSaliguori                 return 2;
117f965509cSaliguori             }
11866f82ceeSKevin Wolf             if (bdrv_pread(bs->file, offset , bs->backing_format,
119f965509cSaliguori                            ext.len) != ext.len)
120f965509cSaliguori                 return 3;
121f965509cSaliguori             bs->backing_format[ext.len] = '\0';
122f965509cSaliguori #ifdef DEBUG_EXT
123f965509cSaliguori             printf("Qcow2: Got format extension %s\n", bs->backing_format);
124f965509cSaliguori #endif
125e1c7f0e3SKevin Wolf             offset = ((offset + ext.len + 7) & ~7);
126f965509cSaliguori             break;
127f965509cSaliguori 
1289b80ddf3Saliguori         default:
1299b80ddf3Saliguori             /* unknown magic -- just skip it */
130e1c7f0e3SKevin Wolf             offset = ((offset + ext.len + 7) & ~7);
1319b80ddf3Saliguori             break;
1329b80ddf3Saliguori         }
1339b80ddf3Saliguori     }
1349b80ddf3Saliguori 
1359b80ddf3Saliguori     return 0;
1369b80ddf3Saliguori }
1379b80ddf3Saliguori 
1389b80ddf3Saliguori 
13966f82ceeSKevin Wolf static int qcow_open(BlockDriverState *bs, int flags)
140585f8587Sbellard {
141585f8587Sbellard     BDRVQcowState *s = bs->opaque;
142419b19d9SStefan Hajnoczi     int len, i;
143585f8587Sbellard     QCowHeader header;
1449b80ddf3Saliguori     uint64_t ext_end;
145585f8587Sbellard 
14666f82ceeSKevin Wolf     if (bdrv_pread(bs->file, 0, &header, sizeof(header)) != sizeof(header))
147585f8587Sbellard         goto fail;
148585f8587Sbellard     be32_to_cpus(&header.magic);
149585f8587Sbellard     be32_to_cpus(&header.version);
150585f8587Sbellard     be64_to_cpus(&header.backing_file_offset);
151585f8587Sbellard     be32_to_cpus(&header.backing_file_size);
152585f8587Sbellard     be64_to_cpus(&header.size);
153585f8587Sbellard     be32_to_cpus(&header.cluster_bits);
154585f8587Sbellard     be32_to_cpus(&header.crypt_method);
155585f8587Sbellard     be64_to_cpus(&header.l1_table_offset);
156585f8587Sbellard     be32_to_cpus(&header.l1_size);
157585f8587Sbellard     be64_to_cpus(&header.refcount_table_offset);
158585f8587Sbellard     be32_to_cpus(&header.refcount_table_clusters);
159585f8587Sbellard     be64_to_cpus(&header.snapshots_offset);
160585f8587Sbellard     be32_to_cpus(&header.nb_snapshots);
161585f8587Sbellard 
162585f8587Sbellard     if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
163585f8587Sbellard         goto fail;
164d191d12dSStefan Weil     if (header.cluster_bits < MIN_CLUSTER_BITS ||
16573c632edSKevin Wolf         header.cluster_bits > MAX_CLUSTER_BITS)
166585f8587Sbellard         goto fail;
167585f8587Sbellard     if (header.crypt_method > QCOW_CRYPT_AES)
168585f8587Sbellard         goto fail;
169585f8587Sbellard     s->crypt_method_header = header.crypt_method;
170585f8587Sbellard     if (s->crypt_method_header)
171585f8587Sbellard         bs->encrypted = 1;
172585f8587Sbellard     s->cluster_bits = header.cluster_bits;
173585f8587Sbellard     s->cluster_size = 1 << s->cluster_bits;
174585f8587Sbellard     s->cluster_sectors = 1 << (s->cluster_bits - 9);
175585f8587Sbellard     s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
176585f8587Sbellard     s->l2_size = 1 << s->l2_bits;
177585f8587Sbellard     bs->total_sectors = header.size / 512;
178585f8587Sbellard     s->csize_shift = (62 - (s->cluster_bits - 8));
179585f8587Sbellard     s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
180585f8587Sbellard     s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
181585f8587Sbellard     s->refcount_table_offset = header.refcount_table_offset;
182585f8587Sbellard     s->refcount_table_size =
183585f8587Sbellard         header.refcount_table_clusters << (s->cluster_bits - 3);
184585f8587Sbellard 
185585f8587Sbellard     s->snapshots_offset = header.snapshots_offset;
186585f8587Sbellard     s->nb_snapshots = header.nb_snapshots;
187585f8587Sbellard 
188585f8587Sbellard     /* read the level 1 table */
189585f8587Sbellard     s->l1_size = header.l1_size;
190419b19d9SStefan Hajnoczi     s->l1_vm_state_index = size_to_l1(s, header.size);
191585f8587Sbellard     /* the L1 table must contain at least enough entries to put
192585f8587Sbellard        header.size bytes */
193585f8587Sbellard     if (s->l1_size < s->l1_vm_state_index)
194585f8587Sbellard         goto fail;
195585f8587Sbellard     s->l1_table_offset = header.l1_table_offset;
196d191d12dSStefan Weil     if (s->l1_size > 0) {
1973f6a3ee5SKevin Wolf         s->l1_table = qemu_mallocz(
1983f6a3ee5SKevin Wolf             align_offset(s->l1_size * sizeof(uint64_t), 512));
19966f82ceeSKevin Wolf         if (bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
200585f8587Sbellard             s->l1_size * sizeof(uint64_t))
201585f8587Sbellard             goto fail;
202585f8587Sbellard         for(i = 0;i < s->l1_size; i++) {
203585f8587Sbellard             be64_to_cpus(&s->l1_table[i]);
204585f8587Sbellard         }
205d191d12dSStefan Weil     }
206585f8587Sbellard     /* alloc L2 cache */
207585f8587Sbellard     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
208585f8587Sbellard     s->cluster_cache = qemu_malloc(s->cluster_size);
209585f8587Sbellard     /* one more sector for decompressed data alignment */
210095a9c58Saliguori     s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
211095a9c58Saliguori                                   + 512);
212585f8587Sbellard     s->cluster_cache_offset = -1;
213585f8587Sbellard 
214ed6ccf0fSKevin Wolf     if (qcow2_refcount_init(bs) < 0)
215585f8587Sbellard         goto fail;
216585f8587Sbellard 
21772cf2d4fSBlue Swirl     QLIST_INIT(&s->cluster_allocs);
218f214978aSKevin Wolf 
2199b80ddf3Saliguori     /* read qcow2 extensions */
2209b80ddf3Saliguori     if (header.backing_file_offset)
2219b80ddf3Saliguori         ext_end = header.backing_file_offset;
2229b80ddf3Saliguori     else
2239b80ddf3Saliguori         ext_end = s->cluster_size;
2249b80ddf3Saliguori     if (qcow_read_extensions(bs, sizeof(header), ext_end))
2259b80ddf3Saliguori         goto fail;
2269b80ddf3Saliguori 
227585f8587Sbellard     /* read the backing file name */
228585f8587Sbellard     if (header.backing_file_offset != 0) {
229585f8587Sbellard         len = header.backing_file_size;
230585f8587Sbellard         if (len > 1023)
231585f8587Sbellard             len = 1023;
23266f82ceeSKevin Wolf         if (bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len) != len)
233585f8587Sbellard             goto fail;
234585f8587Sbellard         bs->backing_file[len] = '\0';
235585f8587Sbellard     }
236ed6ccf0fSKevin Wolf     if (qcow2_read_snapshots(bs) < 0)
237585f8587Sbellard         goto fail;
238585f8587Sbellard 
239585f8587Sbellard #ifdef DEBUG_ALLOC
24014899cdfSFilip Navara     qcow2_check_refcounts(bs);
241585f8587Sbellard #endif
242585f8587Sbellard     return 0;
243585f8587Sbellard 
244585f8587Sbellard  fail:
245ed6ccf0fSKevin Wolf     qcow2_free_snapshots(bs);
246ed6ccf0fSKevin Wolf     qcow2_refcount_close(bs);
247585f8587Sbellard     qemu_free(s->l1_table);
248585f8587Sbellard     qemu_free(s->l2_cache);
249585f8587Sbellard     qemu_free(s->cluster_cache);
250585f8587Sbellard     qemu_free(s->cluster_data);
251585f8587Sbellard     return -1;
252585f8587Sbellard }
253585f8587Sbellard 
254585f8587Sbellard static int qcow_set_key(BlockDriverState *bs, const char *key)
255585f8587Sbellard {
256585f8587Sbellard     BDRVQcowState *s = bs->opaque;
257585f8587Sbellard     uint8_t keybuf[16];
258585f8587Sbellard     int len, i;
259585f8587Sbellard 
260585f8587Sbellard     memset(keybuf, 0, 16);
261585f8587Sbellard     len = strlen(key);
262585f8587Sbellard     if (len > 16)
263585f8587Sbellard         len = 16;
264585f8587Sbellard     /* XXX: we could compress the chars to 7 bits to increase
265585f8587Sbellard        entropy */
266585f8587Sbellard     for(i = 0;i < len;i++) {
267585f8587Sbellard         keybuf[i] = key[i];
268585f8587Sbellard     }
269585f8587Sbellard     s->crypt_method = s->crypt_method_header;
270585f8587Sbellard 
271585f8587Sbellard     if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
272585f8587Sbellard         return -1;
273585f8587Sbellard     if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
274585f8587Sbellard         return -1;
275585f8587Sbellard #if 0
276585f8587Sbellard     /* test */
277585f8587Sbellard     {
278585f8587Sbellard         uint8_t in[16];
279585f8587Sbellard         uint8_t out[16];
280585f8587Sbellard         uint8_t tmp[16];
281585f8587Sbellard         for(i=0;i<16;i++)
282585f8587Sbellard             in[i] = i;
283585f8587Sbellard         AES_encrypt(in, tmp, &s->aes_encrypt_key);
284585f8587Sbellard         AES_decrypt(tmp, out, &s->aes_decrypt_key);
285585f8587Sbellard         for(i = 0; i < 16; i++)
286585f8587Sbellard             printf(" %02x", tmp[i]);
287585f8587Sbellard         printf("\n");
288585f8587Sbellard         for(i = 0; i < 16; i++)
289585f8587Sbellard             printf(" %02x", out[i]);
290585f8587Sbellard         printf("\n");
291585f8587Sbellard     }
292585f8587Sbellard #endif
293585f8587Sbellard     return 0;
294585f8587Sbellard }
295585f8587Sbellard 
296585f8587Sbellard static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
297585f8587Sbellard                              int nb_sectors, int *pnum)
298585f8587Sbellard {
299585f8587Sbellard     uint64_t cluster_offset;
300*1c46efaaSKevin Wolf     int ret;
301585f8587Sbellard 
302095a9c58Saliguori     *pnum = nb_sectors;
303*1c46efaaSKevin Wolf     /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
304*1c46efaaSKevin Wolf      * pass them on today */
305*1c46efaaSKevin Wolf     ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
306*1c46efaaSKevin Wolf     if (ret < 0) {
307*1c46efaaSKevin Wolf         *pnum = 0;
308*1c46efaaSKevin Wolf     }
309095a9c58Saliguori 
310585f8587Sbellard     return (cluster_offset != 0);
311585f8587Sbellard }
312585f8587Sbellard 
313a9465922Sbellard /* handle reading after the end of the backing file */
314ed6ccf0fSKevin Wolf int qcow2_backing_read1(BlockDriverState *bs,
315a9465922Sbellard                   int64_t sector_num, uint8_t *buf, int nb_sectors)
316a9465922Sbellard {
317a9465922Sbellard     int n1;
318a9465922Sbellard     if ((sector_num + nb_sectors) <= bs->total_sectors)
319a9465922Sbellard         return nb_sectors;
320a9465922Sbellard     if (sector_num >= bs->total_sectors)
321a9465922Sbellard         n1 = 0;
322a9465922Sbellard     else
323a9465922Sbellard         n1 = bs->total_sectors - sector_num;
324a9465922Sbellard     memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
325a9465922Sbellard     return n1;
326a9465922Sbellard }
327a9465922Sbellard 
328ce1a14dcSpbrook typedef struct QCowAIOCB {
329ce1a14dcSpbrook     BlockDriverAIOCB common;
330585f8587Sbellard     int64_t sector_num;
331f141eafeSaliguori     QEMUIOVector *qiov;
332585f8587Sbellard     uint8_t *buf;
333f141eafeSaliguori     void *orig_buf;
3347b88e48bSChristoph Hellwig     int remaining_sectors;
3357b88e48bSChristoph Hellwig     int cur_nr_sectors;	/* number of sectors in current iteration */
336585f8587Sbellard     uint64_t cluster_offset;
337585f8587Sbellard     uint8_t *cluster_data;
338585f8587Sbellard     BlockDriverAIOCB *hd_aiocb;
339c87c0672Saliguori     struct iovec hd_iov;
340c87c0672Saliguori     QEMUIOVector hd_qiov;
3411490791fSaliguori     QEMUBH *bh;
342e976c6a1Saliguori     QCowL2Meta l2meta;
34372cf2d4fSBlue Swirl     QLIST_ENTRY(QCowAIOCB) next_depend;
344585f8587Sbellard } QCowAIOCB;
345585f8587Sbellard 
346c16b5a2cSChristoph Hellwig static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
347c16b5a2cSChristoph Hellwig {
348b666d239SKevin Wolf     QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common);
349c16b5a2cSChristoph Hellwig     if (acb->hd_aiocb)
350c16b5a2cSChristoph Hellwig         bdrv_aio_cancel(acb->hd_aiocb);
351c16b5a2cSChristoph Hellwig     qemu_aio_release(acb);
352c16b5a2cSChristoph Hellwig }
353c16b5a2cSChristoph Hellwig 
354c16b5a2cSChristoph Hellwig static AIOPool qcow_aio_pool = {
355c16b5a2cSChristoph Hellwig     .aiocb_size         = sizeof(QCowAIOCB),
356c16b5a2cSChristoph Hellwig     .cancel             = qcow_aio_cancel,
357c16b5a2cSChristoph Hellwig };
358c16b5a2cSChristoph Hellwig 
3591490791fSaliguori static void qcow_aio_read_cb(void *opaque, int ret);
3601490791fSaliguori static void qcow_aio_read_bh(void *opaque)
3611490791fSaliguori {
3621490791fSaliguori     QCowAIOCB *acb = opaque;
3631490791fSaliguori     qemu_bh_delete(acb->bh);
3641490791fSaliguori     acb->bh = NULL;
3651490791fSaliguori     qcow_aio_read_cb(opaque, 0);
3661490791fSaliguori }
3671490791fSaliguori 
368a32ef786Saliguori static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
369a32ef786Saliguori {
370a32ef786Saliguori     if (acb->bh)
371a32ef786Saliguori         return -EIO;
372a32ef786Saliguori 
373a32ef786Saliguori     acb->bh = qemu_bh_new(cb, acb);
374a32ef786Saliguori     if (!acb->bh)
375a32ef786Saliguori         return -EIO;
376a32ef786Saliguori 
377a32ef786Saliguori     qemu_bh_schedule(acb->bh);
378a32ef786Saliguori 
379a32ef786Saliguori     return 0;
380a32ef786Saliguori }
381a32ef786Saliguori 
382585f8587Sbellard static void qcow_aio_read_cb(void *opaque, int ret)
383585f8587Sbellard {
384ce1a14dcSpbrook     QCowAIOCB *acb = opaque;
385ce1a14dcSpbrook     BlockDriverState *bs = acb->common.bs;
386585f8587Sbellard     BDRVQcowState *s = bs->opaque;
387a9465922Sbellard     int index_in_cluster, n1;
388585f8587Sbellard 
389ce1a14dcSpbrook     acb->hd_aiocb = NULL;
390f141eafeSaliguori     if (ret < 0)
391f141eafeSaliguori         goto done;
392585f8587Sbellard 
393585f8587Sbellard     /* post process the read buffer */
394ce1a14dcSpbrook     if (!acb->cluster_offset) {
395585f8587Sbellard         /* nothing to do */
396ce1a14dcSpbrook     } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
397585f8587Sbellard         /* nothing to do */
398585f8587Sbellard     } else {
399585f8587Sbellard         if (s->crypt_method) {
400ed6ccf0fSKevin Wolf             qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
4017b88e48bSChristoph Hellwig                             acb->cur_nr_sectors, 0,
402585f8587Sbellard                             &s->aes_decrypt_key);
403585f8587Sbellard         }
404585f8587Sbellard     }
405585f8587Sbellard 
4067b88e48bSChristoph Hellwig     acb->remaining_sectors -= acb->cur_nr_sectors;
4077b88e48bSChristoph Hellwig     acb->sector_num += acb->cur_nr_sectors;
4087b88e48bSChristoph Hellwig     acb->buf += acb->cur_nr_sectors * 512;
409585f8587Sbellard 
4107b88e48bSChristoph Hellwig     if (acb->remaining_sectors == 0) {
411585f8587Sbellard         /* request completed */
412f141eafeSaliguori         ret = 0;
413f141eafeSaliguori         goto done;
414585f8587Sbellard     }
415585f8587Sbellard 
416585f8587Sbellard     /* prepare next AIO request */
4177b88e48bSChristoph Hellwig     acb->cur_nr_sectors = acb->remaining_sectors;
418*1c46efaaSKevin Wolf     ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
419*1c46efaaSKevin Wolf         &acb->cur_nr_sectors, &acb->cluster_offset);
420*1c46efaaSKevin Wolf     if (ret < 0) {
421*1c46efaaSKevin Wolf         goto done;
422*1c46efaaSKevin Wolf     }
423*1c46efaaSKevin Wolf 
424095a9c58Saliguori     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
425585f8587Sbellard 
426ce1a14dcSpbrook     if (!acb->cluster_offset) {
427585f8587Sbellard         if (bs->backing_hd) {
428585f8587Sbellard             /* read from the base image */
429ed6ccf0fSKevin Wolf             n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num,
4307b88e48bSChristoph Hellwig                                acb->buf, acb->cur_nr_sectors);
431a9465922Sbellard             if (n1 > 0) {
4323f4cb3d3Sblueswir1                 acb->hd_iov.iov_base = (void *)acb->buf;
4337b88e48bSChristoph Hellwig                 acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
434c87c0672Saliguori                 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
43566f82ceeSKevin Wolf                 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
436c87c0672Saliguori                 acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
4377b88e48bSChristoph Hellwig                                     &acb->hd_qiov, acb->cur_nr_sectors,
438c87c0672Saliguori 				    qcow_aio_read_cb, acb);
439ce1a14dcSpbrook                 if (acb->hd_aiocb == NULL)
440f141eafeSaliguori                     goto done;
441585f8587Sbellard             } else {
442a32ef786Saliguori                 ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
443a32ef786Saliguori                 if (ret < 0)
444f141eafeSaliguori                     goto done;
4451490791fSaliguori             }
446a9465922Sbellard         } else {
447585f8587Sbellard             /* Note: in this case, no need to wait */
4487b88e48bSChristoph Hellwig             memset(acb->buf, 0, 512 * acb->cur_nr_sectors);
449a32ef786Saliguori             ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
450a32ef786Saliguori             if (ret < 0)
451f141eafeSaliguori                 goto done;
4521490791fSaliguori         }
453ce1a14dcSpbrook     } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
454585f8587Sbellard         /* add AIO support for compressed blocks ? */
45566f82ceeSKevin Wolf         if (qcow2_decompress_cluster(bs, acb->cluster_offset) < 0)
456f141eafeSaliguori             goto done;
4577b88e48bSChristoph Hellwig         memcpy(acb->buf, s->cluster_cache + index_in_cluster * 512,
4587b88e48bSChristoph Hellwig                512 * acb->cur_nr_sectors);
459a32ef786Saliguori         ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
460a32ef786Saliguori         if (ret < 0)
461f141eafeSaliguori             goto done;
462585f8587Sbellard     } else {
463ce1a14dcSpbrook         if ((acb->cluster_offset & 511) != 0) {
464585f8587Sbellard             ret = -EIO;
465f141eafeSaliguori             goto done;
466585f8587Sbellard         }
467c87c0672Saliguori 
4683f4cb3d3Sblueswir1         acb->hd_iov.iov_base = (void *)acb->buf;
4697b88e48bSChristoph Hellwig         acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
470c87c0672Saliguori         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
47166f82ceeSKevin Wolf         BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
47266f82ceeSKevin Wolf         acb->hd_aiocb = bdrv_aio_readv(bs->file,
473ce1a14dcSpbrook                             (acb->cluster_offset >> 9) + index_in_cluster,
4747b88e48bSChristoph Hellwig                             &acb->hd_qiov, acb->cur_nr_sectors,
4757b88e48bSChristoph Hellwig                             qcow_aio_read_cb, acb);
476171e3d6bSKevin Wolf         if (acb->hd_aiocb == NULL) {
477171e3d6bSKevin Wolf             ret = -EIO;
478f141eafeSaliguori             goto done;
479585f8587Sbellard         }
480171e3d6bSKevin Wolf     }
481f141eafeSaliguori 
482f141eafeSaliguori     return;
483f141eafeSaliguori done:
484f141eafeSaliguori     if (acb->qiov->niov > 1) {
485f141eafeSaliguori         qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
486f141eafeSaliguori         qemu_vfree(acb->orig_buf);
487f141eafeSaliguori     }
488f141eafeSaliguori     acb->common.cb(acb->common.opaque, ret);
489f141eafeSaliguori     qemu_aio_release(acb);
490585f8587Sbellard }
491585f8587Sbellard 
492ce1a14dcSpbrook static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
493f141eafeSaliguori         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
494f141eafeSaliguori         BlockDriverCompletionFunc *cb, void *opaque, int is_write)
495585f8587Sbellard {
496ce1a14dcSpbrook     QCowAIOCB *acb;
497585f8587Sbellard 
498c16b5a2cSChristoph Hellwig     acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
499ce1a14dcSpbrook     if (!acb)
500ce1a14dcSpbrook         return NULL;
501ce1a14dcSpbrook     acb->hd_aiocb = NULL;
502ce1a14dcSpbrook     acb->sector_num = sector_num;
503f141eafeSaliguori     acb->qiov = qiov;
504f141eafeSaliguori     if (qiov->niov > 1) {
505e268ca52Saliguori         acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
506f141eafeSaliguori         if (is_write)
507f141eafeSaliguori             qemu_iovec_to_buffer(qiov, acb->buf);
5083f4cb3d3Sblueswir1     } else {
5093f4cb3d3Sblueswir1         acb->buf = (uint8_t *)qiov->iov->iov_base;
5103f4cb3d3Sblueswir1     }
5117b88e48bSChristoph Hellwig     acb->remaining_sectors = nb_sectors;
5127b88e48bSChristoph Hellwig     acb->cur_nr_sectors = 0;
513ce1a14dcSpbrook     acb->cluster_offset = 0;
514e976c6a1Saliguori     acb->l2meta.nb_clusters = 0;
51572cf2d4fSBlue Swirl     QLIST_INIT(&acb->l2meta.dependent_requests);
516ce1a14dcSpbrook     return acb;
517ce1a14dcSpbrook }
518ce1a14dcSpbrook 
519f141eafeSaliguori static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
520f141eafeSaliguori         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
521ce1a14dcSpbrook         BlockDriverCompletionFunc *cb, void *opaque)
522ce1a14dcSpbrook {
523ce1a14dcSpbrook     QCowAIOCB *acb;
524ce1a14dcSpbrook 
525f141eafeSaliguori     acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
526ce1a14dcSpbrook     if (!acb)
527ce1a14dcSpbrook         return NULL;
528585f8587Sbellard 
529585f8587Sbellard     qcow_aio_read_cb(acb, 0);
530ce1a14dcSpbrook     return &acb->common;
531585f8587Sbellard }
532585f8587Sbellard 
533f214978aSKevin Wolf static void qcow_aio_write_cb(void *opaque, int ret);
534f214978aSKevin Wolf 
535f214978aSKevin Wolf static void run_dependent_requests(QCowL2Meta *m)
536f214978aSKevin Wolf {
537f214978aSKevin Wolf     QCowAIOCB *req;
538f214978aSKevin Wolf     QCowAIOCB *next;
539f214978aSKevin Wolf 
540f214978aSKevin Wolf     /* Take the request off the list of running requests */
541f214978aSKevin Wolf     if (m->nb_clusters != 0) {
54272cf2d4fSBlue Swirl         QLIST_REMOVE(m, next_in_flight);
543f214978aSKevin Wolf     }
544f214978aSKevin Wolf 
545d4c146f0SStefan Hajnoczi     /* Restart all dependent requests */
546d4c146f0SStefan Hajnoczi     QLIST_FOREACH_SAFE(req, &m->dependent_requests, next_depend, next) {
547f214978aSKevin Wolf         qcow_aio_write_cb(req, 0);
548f214978aSKevin Wolf     }
549f214978aSKevin Wolf 
550f214978aSKevin Wolf     /* Empty the list for the next part of the request */
55172cf2d4fSBlue Swirl     QLIST_INIT(&m->dependent_requests);
552f214978aSKevin Wolf }
553f214978aSKevin Wolf 
554585f8587Sbellard static void qcow_aio_write_cb(void *opaque, int ret)
555585f8587Sbellard {
556ce1a14dcSpbrook     QCowAIOCB *acb = opaque;
557ce1a14dcSpbrook     BlockDriverState *bs = acb->common.bs;
558585f8587Sbellard     BDRVQcowState *s = bs->opaque;
559585f8587Sbellard     int index_in_cluster;
560585f8587Sbellard     const uint8_t *src_buf;
561095a9c58Saliguori     int n_end;
562585f8587Sbellard 
563ce1a14dcSpbrook     acb->hd_aiocb = NULL;
564ce1a14dcSpbrook 
565f214978aSKevin Wolf     if (ret >= 0) {
566148da7eaSKevin Wolf         ret = qcow2_alloc_cluster_link_l2(bs, &acb->l2meta);
567f214978aSKevin Wolf     }
568f214978aSKevin Wolf 
569f214978aSKevin Wolf     run_dependent_requests(&acb->l2meta);
570f214978aSKevin Wolf 
571f141eafeSaliguori     if (ret < 0)
572f141eafeSaliguori         goto done;
573585f8587Sbellard 
5747b88e48bSChristoph Hellwig     acb->remaining_sectors -= acb->cur_nr_sectors;
5757b88e48bSChristoph Hellwig     acb->sector_num += acb->cur_nr_sectors;
5767b88e48bSChristoph Hellwig     acb->buf += acb->cur_nr_sectors * 512;
577585f8587Sbellard 
5787b88e48bSChristoph Hellwig     if (acb->remaining_sectors == 0) {
579585f8587Sbellard         /* request completed */
580f141eafeSaliguori         ret = 0;
581f141eafeSaliguori         goto done;
582585f8587Sbellard     }
583585f8587Sbellard 
584ce1a14dcSpbrook     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
5857b88e48bSChristoph Hellwig     n_end = index_in_cluster + acb->remaining_sectors;
586095a9c58Saliguori     if (s->crypt_method &&
587095a9c58Saliguori         n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
588095a9c58Saliguori         n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
589095a9c58Saliguori 
590148da7eaSKevin Wolf     ret = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
5917b88e48bSChristoph Hellwig         index_in_cluster, n_end, &acb->cur_nr_sectors, &acb->l2meta);
592148da7eaSKevin Wolf     if (ret < 0) {
593148da7eaSKevin Wolf         goto done;
594148da7eaSKevin Wolf     }
595148da7eaSKevin Wolf 
596148da7eaSKevin Wolf     acb->cluster_offset = acb->l2meta.cluster_offset;
597f214978aSKevin Wolf 
598f214978aSKevin Wolf     /* Need to wait for another request? If so, we are done for now. */
599148da7eaSKevin Wolf     if (acb->l2meta.nb_clusters == 0 && acb->l2meta.depends_on != NULL) {
60072cf2d4fSBlue Swirl         QLIST_INSERT_HEAD(&acb->l2meta.depends_on->dependent_requests,
601f214978aSKevin Wolf             acb, next_depend);
602f214978aSKevin Wolf         return;
603f214978aSKevin Wolf     }
604f214978aSKevin Wolf 
605148da7eaSKevin Wolf     assert((acb->cluster_offset & 511) == 0);
606148da7eaSKevin Wolf 
607585f8587Sbellard     if (s->crypt_method) {
608ce1a14dcSpbrook         if (!acb->cluster_data) {
609095a9c58Saliguori             acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
610095a9c58Saliguori                                              s->cluster_size);
611585f8587Sbellard         }
612ed6ccf0fSKevin Wolf         qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
6137b88e48bSChristoph Hellwig                         acb->cur_nr_sectors, 1, &s->aes_encrypt_key);
614ce1a14dcSpbrook         src_buf = acb->cluster_data;
615585f8587Sbellard     } else {
616ce1a14dcSpbrook         src_buf = acb->buf;
617585f8587Sbellard     }
618c87c0672Saliguori     acb->hd_iov.iov_base = (void *)src_buf;
6197b88e48bSChristoph Hellwig     acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
620c87c0672Saliguori     qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
62166f82ceeSKevin Wolf     BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
62266f82ceeSKevin Wolf     acb->hd_aiocb = bdrv_aio_writev(bs->file,
623e976c6a1Saliguori                                     (acb->cluster_offset >> 9) + index_in_cluster,
6247b88e48bSChristoph Hellwig                                     &acb->hd_qiov, acb->cur_nr_sectors,
625585f8587Sbellard                                     qcow_aio_write_cb, acb);
626171e3d6bSKevin Wolf     if (acb->hd_aiocb == NULL) {
627171e3d6bSKevin Wolf         ret = -EIO;
628c644db3dSKevin Wolf         goto fail;
629171e3d6bSKevin Wolf     }
630f141eafeSaliguori 
631f141eafeSaliguori     return;
632f141eafeSaliguori 
633c644db3dSKevin Wolf fail:
634c644db3dSKevin Wolf     if (acb->l2meta.nb_clusters != 0) {
635c644db3dSKevin Wolf         QLIST_REMOVE(&acb->l2meta, next_in_flight);
636c644db3dSKevin Wolf     }
637f141eafeSaliguori done:
638f141eafeSaliguori     if (acb->qiov->niov > 1)
639f141eafeSaliguori         qemu_vfree(acb->orig_buf);
640f141eafeSaliguori     acb->common.cb(acb->common.opaque, ret);
641f141eafeSaliguori     qemu_aio_release(acb);
642585f8587Sbellard }
643585f8587Sbellard 
644f141eafeSaliguori static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
645f141eafeSaliguori         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
646ce1a14dcSpbrook         BlockDriverCompletionFunc *cb, void *opaque)
647585f8587Sbellard {
648585f8587Sbellard     BDRVQcowState *s = bs->opaque;
649ce1a14dcSpbrook     QCowAIOCB *acb;
650585f8587Sbellard 
651585f8587Sbellard     s->cluster_cache_offset = -1; /* disable compressed cache */
652585f8587Sbellard 
653f141eafeSaliguori     acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
654ce1a14dcSpbrook     if (!acb)
655ce1a14dcSpbrook         return NULL;
656585f8587Sbellard 
657585f8587Sbellard     qcow_aio_write_cb(acb, 0);
658ce1a14dcSpbrook     return &acb->common;
659585f8587Sbellard }
660585f8587Sbellard 
661585f8587Sbellard static void qcow_close(BlockDriverState *bs)
662585f8587Sbellard {
663585f8587Sbellard     BDRVQcowState *s = bs->opaque;
664585f8587Sbellard     qemu_free(s->l1_table);
665585f8587Sbellard     qemu_free(s->l2_cache);
666585f8587Sbellard     qemu_free(s->cluster_cache);
667585f8587Sbellard     qemu_free(s->cluster_data);
668ed6ccf0fSKevin Wolf     qcow2_refcount_close(bs);
669585f8587Sbellard }
670585f8587Sbellard 
671756e6736SKevin Wolf /*
672756e6736SKevin Wolf  * Updates the variable length parts of the qcow2 header, i.e. the backing file
673756e6736SKevin Wolf  * name and all extensions. qcow2 was not designed to allow such changes, so if
674756e6736SKevin Wolf  * we run out of space (we can only use the first cluster) this function may
675756e6736SKevin Wolf  * fail.
676756e6736SKevin Wolf  *
677756e6736SKevin Wolf  * Returns 0 on success, -errno in error cases.
678756e6736SKevin Wolf  */
679756e6736SKevin Wolf static int qcow2_update_ext_header(BlockDriverState *bs,
680756e6736SKevin Wolf     const char *backing_file, const char *backing_fmt)
681756e6736SKevin Wolf {
682756e6736SKevin Wolf     size_t backing_file_len = 0;
683756e6736SKevin Wolf     size_t backing_fmt_len = 0;
684756e6736SKevin Wolf     BDRVQcowState *s = bs->opaque;
685756e6736SKevin Wolf     QCowExtension ext_backing_fmt = {0, 0};
686756e6736SKevin Wolf     int ret;
687756e6736SKevin Wolf 
688756e6736SKevin Wolf     /* Backing file format doesn't make sense without a backing file */
689756e6736SKevin Wolf     if (backing_fmt && !backing_file) {
690756e6736SKevin Wolf         return -EINVAL;
691756e6736SKevin Wolf     }
692756e6736SKevin Wolf 
693756e6736SKevin Wolf     /* Prepare the backing file format extension if needed */
694756e6736SKevin Wolf     if (backing_fmt) {
695756e6736SKevin Wolf         ext_backing_fmt.len = cpu_to_be32(strlen(backing_fmt));
696756e6736SKevin Wolf         ext_backing_fmt.magic = cpu_to_be32(QCOW_EXT_MAGIC_BACKING_FORMAT);
697756e6736SKevin Wolf         backing_fmt_len = ((sizeof(ext_backing_fmt)
698756e6736SKevin Wolf             + strlen(backing_fmt) + 7) & ~7);
699756e6736SKevin Wolf     }
700756e6736SKevin Wolf 
701756e6736SKevin Wolf     /* Check if we can fit the new header into the first cluster */
702756e6736SKevin Wolf     if (backing_file) {
703756e6736SKevin Wolf         backing_file_len = strlen(backing_file);
704756e6736SKevin Wolf     }
705756e6736SKevin Wolf 
706756e6736SKevin Wolf     size_t header_size = sizeof(QCowHeader) + backing_file_len
707756e6736SKevin Wolf         + backing_fmt_len;
708756e6736SKevin Wolf 
709756e6736SKevin Wolf     if (header_size > s->cluster_size) {
710756e6736SKevin Wolf         return -ENOSPC;
711756e6736SKevin Wolf     }
712756e6736SKevin Wolf 
713756e6736SKevin Wolf     /* Rewrite backing file name and qcow2 extensions */
714756e6736SKevin Wolf     size_t ext_size = header_size - sizeof(QCowHeader);
715756e6736SKevin Wolf     uint8_t buf[ext_size];
716756e6736SKevin Wolf     size_t offset = 0;
717756e6736SKevin Wolf     size_t backing_file_offset = 0;
718756e6736SKevin Wolf 
719756e6736SKevin Wolf     if (backing_file) {
720756e6736SKevin Wolf         if (backing_fmt) {
721756e6736SKevin Wolf             int padding = backing_fmt_len -
722756e6736SKevin Wolf                 (sizeof(ext_backing_fmt) + strlen(backing_fmt));
723756e6736SKevin Wolf 
724756e6736SKevin Wolf             memcpy(buf + offset, &ext_backing_fmt, sizeof(ext_backing_fmt));
725756e6736SKevin Wolf             offset += sizeof(ext_backing_fmt);
726756e6736SKevin Wolf 
727756e6736SKevin Wolf             memcpy(buf + offset, backing_fmt, strlen(backing_fmt));
728756e6736SKevin Wolf             offset += strlen(backing_fmt);
729756e6736SKevin Wolf 
730756e6736SKevin Wolf             memset(buf + offset, 0, padding);
731756e6736SKevin Wolf             offset += padding;
732756e6736SKevin Wolf         }
733756e6736SKevin Wolf 
734756e6736SKevin Wolf         memcpy(buf + offset, backing_file, backing_file_len);
735756e6736SKevin Wolf         backing_file_offset = sizeof(QCowHeader) + offset;
736756e6736SKevin Wolf     }
737756e6736SKevin Wolf 
73866f82ceeSKevin Wolf     ret = bdrv_pwrite(bs->file, sizeof(QCowHeader), buf, ext_size);
739756e6736SKevin Wolf     if (ret < 0) {
740756e6736SKevin Wolf         goto fail;
741756e6736SKevin Wolf     }
742756e6736SKevin Wolf 
743756e6736SKevin Wolf     /* Update header fields */
744756e6736SKevin Wolf     uint64_t be_backing_file_offset = cpu_to_be64(backing_file_offset);
745756e6736SKevin Wolf     uint32_t be_backing_file_size = cpu_to_be32(backing_file_len);
746756e6736SKevin Wolf 
74766f82ceeSKevin Wolf     ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, backing_file_offset),
748756e6736SKevin Wolf         &be_backing_file_offset, sizeof(uint64_t));
749756e6736SKevin Wolf     if (ret < 0) {
750756e6736SKevin Wolf         goto fail;
751756e6736SKevin Wolf     }
752756e6736SKevin Wolf 
75366f82ceeSKevin Wolf     ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, backing_file_size),
754756e6736SKevin Wolf         &be_backing_file_size, sizeof(uint32_t));
755756e6736SKevin Wolf     if (ret < 0) {
756756e6736SKevin Wolf         goto fail;
757756e6736SKevin Wolf     }
758756e6736SKevin Wolf 
759756e6736SKevin Wolf     ret = 0;
760756e6736SKevin Wolf fail:
761756e6736SKevin Wolf     return ret;
762756e6736SKevin Wolf }
763756e6736SKevin Wolf 
764756e6736SKevin Wolf static int qcow2_change_backing_file(BlockDriverState *bs,
765756e6736SKevin Wolf     const char *backing_file, const char *backing_fmt)
766756e6736SKevin Wolf {
767756e6736SKevin Wolf     return qcow2_update_ext_header(bs, backing_file, backing_fmt);
768756e6736SKevin Wolf }
769756e6736SKevin Wolf 
77073c632edSKevin Wolf static int get_bits_from_size(size_t size)
77173c632edSKevin Wolf {
77273c632edSKevin Wolf     int res = 0;
77373c632edSKevin Wolf 
77473c632edSKevin Wolf     if (size == 0) {
77573c632edSKevin Wolf         return -1;
77673c632edSKevin Wolf     }
77773c632edSKevin Wolf 
77873c632edSKevin Wolf     while (size != 1) {
77973c632edSKevin Wolf         /* Not a power of two */
78073c632edSKevin Wolf         if (size & 1) {
78173c632edSKevin Wolf             return -1;
78273c632edSKevin Wolf         }
78373c632edSKevin Wolf 
78473c632edSKevin Wolf         size >>= 1;
78573c632edSKevin Wolf         res++;
78673c632edSKevin Wolf     }
78773c632edSKevin Wolf 
78873c632edSKevin Wolf     return res;
78973c632edSKevin Wolf }
79073c632edSKevin Wolf 
791a35e1c17SKevin Wolf 
792a35e1c17SKevin Wolf static int preallocate(BlockDriverState *bs)
793a35e1c17SKevin Wolf {
794a35e1c17SKevin Wolf     uint64_t nb_sectors;
795a35e1c17SKevin Wolf     uint64_t offset;
796a35e1c17SKevin Wolf     int num;
797148da7eaSKevin Wolf     int ret;
798a35e1c17SKevin Wolf     QCowL2Meta meta;
799a35e1c17SKevin Wolf 
800a35e1c17SKevin Wolf     nb_sectors = bdrv_getlength(bs) >> 9;
801a35e1c17SKevin Wolf     offset = 0;
80272cf2d4fSBlue Swirl     QLIST_INIT(&meta.dependent_requests);
803148da7eaSKevin Wolf     meta.cluster_offset = 0;
804a35e1c17SKevin Wolf 
805a35e1c17SKevin Wolf     while (nb_sectors) {
806a35e1c17SKevin Wolf         num = MIN(nb_sectors, INT_MAX >> 9);
807148da7eaSKevin Wolf         ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
808a35e1c17SKevin Wolf 
809148da7eaSKevin Wolf         if (ret < 0) {
810a35e1c17SKevin Wolf             return -1;
811a35e1c17SKevin Wolf         }
812a35e1c17SKevin Wolf 
813148da7eaSKevin Wolf         if (qcow2_alloc_cluster_link_l2(bs, &meta) < 0) {
814148da7eaSKevin Wolf             qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
815a35e1c17SKevin Wolf             return -1;
816a35e1c17SKevin Wolf         }
817a35e1c17SKevin Wolf 
818f214978aSKevin Wolf         /* There are no dependent requests, but we need to remove our request
819f214978aSKevin Wolf          * from the list of in-flight requests */
820f214978aSKevin Wolf         run_dependent_requests(&meta);
821f214978aSKevin Wolf 
822a35e1c17SKevin Wolf         /* TODO Preallocate data if requested */
823a35e1c17SKevin Wolf 
824a35e1c17SKevin Wolf         nb_sectors -= num;
825a35e1c17SKevin Wolf         offset += num << 9;
826a35e1c17SKevin Wolf     }
827a35e1c17SKevin Wolf 
828a35e1c17SKevin Wolf     /*
829a35e1c17SKevin Wolf      * It is expected that the image file is large enough to actually contain
830a35e1c17SKevin Wolf      * all of the allocated clusters (otherwise we get failing reads after
831a35e1c17SKevin Wolf      * EOF). Extend the image to the last allocated sector.
832a35e1c17SKevin Wolf      */
833148da7eaSKevin Wolf     if (meta.cluster_offset != 0) {
834ea80b906SKevin Wolf         uint8_t buf[512];
835ea80b906SKevin Wolf         memset(buf, 0, 512);
83666f82ceeSKevin Wolf         bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
837a35e1c17SKevin Wolf     }
838a35e1c17SKevin Wolf 
839a35e1c17SKevin Wolf     return 0;
840a35e1c17SKevin Wolf }
841a35e1c17SKevin Wolf 
842de5f3f40SKevin Wolf static int qcow_create2(const char *filename, int64_t total_size,
843de5f3f40SKevin Wolf                         const char *backing_file, const char *backing_format,
844de5f3f40SKevin Wolf                         int flags, size_t cluster_size, int prealloc)
845de5f3f40SKevin Wolf {
846de5f3f40SKevin Wolf 
847de5f3f40SKevin Wolf     int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
848de5f3f40SKevin Wolf     int ref_clusters, reftable_clusters, backing_format_len = 0;
849de5f3f40SKevin Wolf     int rounded_ext_bf_len = 0;
850de5f3f40SKevin Wolf     QCowHeader header;
851de5f3f40SKevin Wolf     uint64_t tmp, offset;
852de5f3f40SKevin Wolf     uint64_t old_ref_clusters;
853de5f3f40SKevin Wolf     QCowCreateState s1, *s = &s1;
854de5f3f40SKevin Wolf     QCowExtension ext_bf = {0, 0};
855de5f3f40SKevin Wolf     int ret;
856de5f3f40SKevin Wolf 
857de5f3f40SKevin Wolf     memset(s, 0, sizeof(*s));
858de5f3f40SKevin Wolf 
859de5f3f40SKevin Wolf     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
860de5f3f40SKevin Wolf     if (fd < 0)
861de5f3f40SKevin Wolf         return -errno;
862de5f3f40SKevin Wolf     memset(&header, 0, sizeof(header));
863de5f3f40SKevin Wolf     header.magic = cpu_to_be32(QCOW_MAGIC);
864de5f3f40SKevin Wolf     header.version = cpu_to_be32(QCOW_VERSION);
865de5f3f40SKevin Wolf     header.size = cpu_to_be64(total_size * 512);
866de5f3f40SKevin Wolf     header_size = sizeof(header);
867de5f3f40SKevin Wolf     backing_filename_len = 0;
868de5f3f40SKevin Wolf     if (backing_file) {
869de5f3f40SKevin Wolf         if (backing_format) {
870de5f3f40SKevin Wolf             ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT;
871de5f3f40SKevin Wolf             backing_format_len = strlen(backing_format);
872de5f3f40SKevin Wolf             ext_bf.len = backing_format_len;
873de5f3f40SKevin Wolf             rounded_ext_bf_len = (sizeof(ext_bf) + ext_bf.len + 7) & ~7;
874de5f3f40SKevin Wolf             header_size += rounded_ext_bf_len;
875de5f3f40SKevin Wolf         }
876de5f3f40SKevin Wolf         header.backing_file_offset = cpu_to_be64(header_size);
877de5f3f40SKevin Wolf         backing_filename_len = strlen(backing_file);
878de5f3f40SKevin Wolf         header.backing_file_size = cpu_to_be32(backing_filename_len);
879de5f3f40SKevin Wolf         header_size += backing_filename_len;
880de5f3f40SKevin Wolf     }
881de5f3f40SKevin Wolf 
882de5f3f40SKevin Wolf     /* Cluster size */
883de5f3f40SKevin Wolf     s->cluster_bits = get_bits_from_size(cluster_size);
884de5f3f40SKevin Wolf     if (s->cluster_bits < MIN_CLUSTER_BITS ||
885de5f3f40SKevin Wolf         s->cluster_bits > MAX_CLUSTER_BITS)
886de5f3f40SKevin Wolf     {
887de5f3f40SKevin Wolf         fprintf(stderr, "Cluster size must be a power of two between "
888de5f3f40SKevin Wolf             "%d and %dk\n",
889de5f3f40SKevin Wolf             1 << MIN_CLUSTER_BITS,
890de5f3f40SKevin Wolf             1 << (MAX_CLUSTER_BITS - 10));
891de5f3f40SKevin Wolf         return -EINVAL;
892de5f3f40SKevin Wolf     }
893de5f3f40SKevin Wolf     s->cluster_size = 1 << s->cluster_bits;
894de5f3f40SKevin Wolf 
895de5f3f40SKevin Wolf     header.cluster_bits = cpu_to_be32(s->cluster_bits);
896de5f3f40SKevin Wolf     header_size = (header_size + 7) & ~7;
897de5f3f40SKevin Wolf     if (flags & BLOCK_FLAG_ENCRYPT) {
898de5f3f40SKevin Wolf         header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
899de5f3f40SKevin Wolf     } else {
900de5f3f40SKevin Wolf         header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
901de5f3f40SKevin Wolf     }
902de5f3f40SKevin Wolf     l2_bits = s->cluster_bits - 3;
903de5f3f40SKevin Wolf     shift = s->cluster_bits + l2_bits;
904de5f3f40SKevin Wolf     l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
905de5f3f40SKevin Wolf     offset = align_offset(header_size, s->cluster_size);
906de5f3f40SKevin Wolf     s->l1_table_offset = offset;
907de5f3f40SKevin Wolf     header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
908de5f3f40SKevin Wolf     header.l1_size = cpu_to_be32(l1_size);
909de5f3f40SKevin Wolf     offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
910de5f3f40SKevin Wolf 
911de5f3f40SKevin Wolf     /* count how many refcount blocks needed */
912de5f3f40SKevin Wolf 
913de5f3f40SKevin Wolf #define NUM_CLUSTERS(bytes) \
914de5f3f40SKevin Wolf     (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
915de5f3f40SKevin Wolf 
916de5f3f40SKevin Wolf     ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
917de5f3f40SKevin Wolf 
918de5f3f40SKevin Wolf     do {
919de5f3f40SKevin Wolf         uint64_t image_clusters;
920de5f3f40SKevin Wolf         old_ref_clusters = ref_clusters;
921de5f3f40SKevin Wolf 
922de5f3f40SKevin Wolf         /* Number of clusters used for the refcount table */
923de5f3f40SKevin Wolf         reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
924de5f3f40SKevin Wolf 
925de5f3f40SKevin Wolf         /* Number of clusters that the whole image will have */
926de5f3f40SKevin Wolf         image_clusters = NUM_CLUSTERS(offset) + ref_clusters
927de5f3f40SKevin Wolf             + reftable_clusters;
928de5f3f40SKevin Wolf 
929de5f3f40SKevin Wolf         /* Number of refcount blocks needed for the image */
930de5f3f40SKevin Wolf         ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
931de5f3f40SKevin Wolf 
932de5f3f40SKevin Wolf     } while (ref_clusters != old_ref_clusters);
933de5f3f40SKevin Wolf 
934de5f3f40SKevin Wolf     s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size);
935de5f3f40SKevin Wolf 
936de5f3f40SKevin Wolf     s->refcount_table_offset = offset;
937de5f3f40SKevin Wolf     header.refcount_table_offset = cpu_to_be64(offset);
938de5f3f40SKevin Wolf     header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
939de5f3f40SKevin Wolf     offset += (reftable_clusters * s->cluster_size);
940de5f3f40SKevin Wolf     s->refcount_block_offset = offset;
941de5f3f40SKevin Wolf 
942de5f3f40SKevin Wolf     for (i=0; i < ref_clusters; i++) {
943de5f3f40SKevin Wolf         s->refcount_table[i] = cpu_to_be64(offset);
944de5f3f40SKevin Wolf         offset += s->cluster_size;
945de5f3f40SKevin Wolf     }
946de5f3f40SKevin Wolf 
947de5f3f40SKevin Wolf     s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size);
948de5f3f40SKevin Wolf 
949de5f3f40SKevin Wolf     /* update refcounts */
950de5f3f40SKevin Wolf     qcow2_create_refcount_update(s, 0, header_size);
951de5f3f40SKevin Wolf     qcow2_create_refcount_update(s, s->l1_table_offset,
952de5f3f40SKevin Wolf         l1_size * sizeof(uint64_t));
953de5f3f40SKevin Wolf     qcow2_create_refcount_update(s, s->refcount_table_offset,
954de5f3f40SKevin Wolf         reftable_clusters * s->cluster_size);
955de5f3f40SKevin Wolf     qcow2_create_refcount_update(s, s->refcount_block_offset,
956de5f3f40SKevin Wolf         ref_clusters * s->cluster_size);
957de5f3f40SKevin Wolf 
958de5f3f40SKevin Wolf     /* write all the data */
959de5f3f40SKevin Wolf     ret = qemu_write_full(fd, &header, sizeof(header));
960de5f3f40SKevin Wolf     if (ret != sizeof(header)) {
961de5f3f40SKevin Wolf         ret = -errno;
962de5f3f40SKevin Wolf         goto exit;
963de5f3f40SKevin Wolf     }
964de5f3f40SKevin Wolf     if (backing_file) {
965de5f3f40SKevin Wolf         if (backing_format_len) {
966de5f3f40SKevin Wolf             char zero[16];
967de5f3f40SKevin Wolf             int padding = rounded_ext_bf_len - (ext_bf.len + sizeof(ext_bf));
968de5f3f40SKevin Wolf 
969de5f3f40SKevin Wolf             memset(zero, 0, sizeof(zero));
970de5f3f40SKevin Wolf             cpu_to_be32s(&ext_bf.magic);
971de5f3f40SKevin Wolf             cpu_to_be32s(&ext_bf.len);
972de5f3f40SKevin Wolf             ret = qemu_write_full(fd, &ext_bf, sizeof(ext_bf));
973de5f3f40SKevin Wolf             if (ret != sizeof(ext_bf)) {
974de5f3f40SKevin Wolf                 ret = -errno;
975de5f3f40SKevin Wolf                 goto exit;
976de5f3f40SKevin Wolf             }
977de5f3f40SKevin Wolf             ret = qemu_write_full(fd, backing_format, backing_format_len);
978de5f3f40SKevin Wolf             if (ret != backing_format_len) {
979de5f3f40SKevin Wolf                 ret = -errno;
980de5f3f40SKevin Wolf                 goto exit;
981de5f3f40SKevin Wolf             }
982de5f3f40SKevin Wolf             if (padding > 0) {
983de5f3f40SKevin Wolf                 ret = qemu_write_full(fd, zero, padding);
984de5f3f40SKevin Wolf                 if (ret != padding) {
985de5f3f40SKevin Wolf                     ret = -errno;
986de5f3f40SKevin Wolf                     goto exit;
987de5f3f40SKevin Wolf                 }
988de5f3f40SKevin Wolf             }
989de5f3f40SKevin Wolf         }
990de5f3f40SKevin Wolf         ret = qemu_write_full(fd, backing_file, backing_filename_len);
991de5f3f40SKevin Wolf         if (ret != backing_filename_len) {
992de5f3f40SKevin Wolf             ret = -errno;
993de5f3f40SKevin Wolf             goto exit;
994de5f3f40SKevin Wolf         }
995de5f3f40SKevin Wolf     }
996de5f3f40SKevin Wolf     lseek(fd, s->l1_table_offset, SEEK_SET);
997de5f3f40SKevin Wolf     tmp = 0;
998de5f3f40SKevin Wolf     for(i = 0;i < l1_size; i++) {
999de5f3f40SKevin Wolf         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
1000de5f3f40SKevin Wolf         if (ret != sizeof(tmp)) {
1001de5f3f40SKevin Wolf             ret = -errno;
1002de5f3f40SKevin Wolf             goto exit;
1003de5f3f40SKevin Wolf         }
1004de5f3f40SKevin Wolf     }
1005de5f3f40SKevin Wolf     lseek(fd, s->refcount_table_offset, SEEK_SET);
1006de5f3f40SKevin Wolf     ret = qemu_write_full(fd, s->refcount_table,
1007de5f3f40SKevin Wolf         reftable_clusters * s->cluster_size);
1008de5f3f40SKevin Wolf     if (ret != reftable_clusters * s->cluster_size) {
1009de5f3f40SKevin Wolf         ret = -errno;
1010de5f3f40SKevin Wolf         goto exit;
1011de5f3f40SKevin Wolf     }
1012de5f3f40SKevin Wolf 
1013de5f3f40SKevin Wolf     lseek(fd, s->refcount_block_offset, SEEK_SET);
1014de5f3f40SKevin Wolf     ret = qemu_write_full(fd, s->refcount_block,
1015de5f3f40SKevin Wolf 		    ref_clusters * s->cluster_size);
1016de5f3f40SKevin Wolf     if (ret != ref_clusters * s->cluster_size) {
1017de5f3f40SKevin Wolf         ret = -errno;
1018de5f3f40SKevin Wolf         goto exit;
1019de5f3f40SKevin Wolf     }
1020de5f3f40SKevin Wolf 
1021de5f3f40SKevin Wolf     ret = 0;
1022de5f3f40SKevin Wolf exit:
1023de5f3f40SKevin Wolf     qemu_free(s->refcount_table);
1024de5f3f40SKevin Wolf     qemu_free(s->refcount_block);
1025de5f3f40SKevin Wolf     close(fd);
1026de5f3f40SKevin Wolf 
1027de5f3f40SKevin Wolf     /* Preallocate metadata */
1028de5f3f40SKevin Wolf     if (ret == 0 && prealloc) {
1029de5f3f40SKevin Wolf         BlockDriverState *bs;
103092b30744SKevin Wolf         BlockDriver *drv = bdrv_find_format("qcow2");
1031de5f3f40SKevin Wolf         bs = bdrv_new("");
103292b30744SKevin Wolf         bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv);
1033de5f3f40SKevin Wolf         preallocate(bs);
1034de5f3f40SKevin Wolf         bdrv_close(bs);
1035de5f3f40SKevin Wolf     }
1036de5f3f40SKevin Wolf 
1037de5f3f40SKevin Wolf     return ret;
1038de5f3f40SKevin Wolf }
1039de5f3f40SKevin Wolf 
1040de5f3f40SKevin Wolf static int qcow_create(const char *filename, QEMUOptionParameter *options)
1041de5f3f40SKevin Wolf {
1042de5f3f40SKevin Wolf     const char *backing_file = NULL;
1043de5f3f40SKevin Wolf     const char *backing_fmt = NULL;
1044de5f3f40SKevin Wolf     uint64_t sectors = 0;
1045de5f3f40SKevin Wolf     int flags = 0;
1046de5f3f40SKevin Wolf     size_t cluster_size = 65536;
1047de5f3f40SKevin Wolf     int prealloc = 0;
1048de5f3f40SKevin Wolf 
1049de5f3f40SKevin Wolf     /* Read out options */
1050de5f3f40SKevin Wolf     while (options && options->name) {
1051de5f3f40SKevin Wolf         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
1052de5f3f40SKevin Wolf             sectors = options->value.n / 512;
1053de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
1054de5f3f40SKevin Wolf             backing_file = options->value.s;
1055de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
1056de5f3f40SKevin Wolf             backing_fmt = options->value.s;
1057de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
1058de5f3f40SKevin Wolf             flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
1059de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
1060de5f3f40SKevin Wolf             if (options->value.n) {
1061de5f3f40SKevin Wolf                 cluster_size = options->value.n;
1062de5f3f40SKevin Wolf             }
1063de5f3f40SKevin Wolf         } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
1064de5f3f40SKevin Wolf             if (!options->value.s || !strcmp(options->value.s, "off")) {
1065de5f3f40SKevin Wolf                 prealloc = 0;
1066de5f3f40SKevin Wolf             } else if (!strcmp(options->value.s, "metadata")) {
1067de5f3f40SKevin Wolf                 prealloc = 1;
1068de5f3f40SKevin Wolf             } else {
1069de5f3f40SKevin Wolf                 fprintf(stderr, "Invalid preallocation mode: '%s'\n",
1070de5f3f40SKevin Wolf                     options->value.s);
1071de5f3f40SKevin Wolf                 return -EINVAL;
1072de5f3f40SKevin Wolf             }
1073de5f3f40SKevin Wolf         }
1074de5f3f40SKevin Wolf         options++;
1075de5f3f40SKevin Wolf     }
1076de5f3f40SKevin Wolf 
1077de5f3f40SKevin Wolf     if (backing_file && prealloc) {
1078de5f3f40SKevin Wolf         fprintf(stderr, "Backing file and preallocation cannot be used at "
1079de5f3f40SKevin Wolf             "the same time\n");
1080de5f3f40SKevin Wolf         return -EINVAL;
1081de5f3f40SKevin Wolf     }
1082de5f3f40SKevin Wolf 
1083de5f3f40SKevin Wolf     return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
1084de5f3f40SKevin Wolf         cluster_size, prealloc);
1085de5f3f40SKevin Wolf }
1086de5f3f40SKevin Wolf 
108720d97356SBlue Swirl static int qcow_make_empty(BlockDriverState *bs)
108820d97356SBlue Swirl {
108920d97356SBlue Swirl #if 0
109020d97356SBlue Swirl     /* XXX: not correct */
109120d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
109220d97356SBlue Swirl     uint32_t l1_length = s->l1_size * sizeof(uint64_t);
109320d97356SBlue Swirl     int ret;
109420d97356SBlue Swirl 
109520d97356SBlue Swirl     memset(s->l1_table, 0, l1_length);
109666f82ceeSKevin Wolf     if (bdrv_pwrite(bs->file, s->l1_table_offset, s->l1_table, l1_length) < 0)
109720d97356SBlue Swirl         return -1;
109866f82ceeSKevin Wolf     ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
109920d97356SBlue Swirl     if (ret < 0)
110020d97356SBlue Swirl         return ret;
110120d97356SBlue Swirl 
110220d97356SBlue Swirl     l2_cache_reset(bs);
110320d97356SBlue Swirl #endif
110420d97356SBlue Swirl     return 0;
110520d97356SBlue Swirl }
110620d97356SBlue Swirl 
1107419b19d9SStefan Hajnoczi static int qcow2_truncate(BlockDriverState *bs, int64_t offset)
1108419b19d9SStefan Hajnoczi {
1109419b19d9SStefan Hajnoczi     BDRVQcowState *s = bs->opaque;
1110419b19d9SStefan Hajnoczi     int ret, new_l1_size;
1111419b19d9SStefan Hajnoczi 
1112419b19d9SStefan Hajnoczi     if (offset & 511) {
1113419b19d9SStefan Hajnoczi         return -EINVAL;
1114419b19d9SStefan Hajnoczi     }
1115419b19d9SStefan Hajnoczi 
1116419b19d9SStefan Hajnoczi     /* cannot proceed if image has snapshots */
1117419b19d9SStefan Hajnoczi     if (s->nb_snapshots) {
1118419b19d9SStefan Hajnoczi         return -ENOTSUP;
1119419b19d9SStefan Hajnoczi     }
1120419b19d9SStefan Hajnoczi 
1121419b19d9SStefan Hajnoczi     /* shrinking is currently not supported */
1122419b19d9SStefan Hajnoczi     if (offset < bs->total_sectors * 512) {
1123419b19d9SStefan Hajnoczi         return -ENOTSUP;
1124419b19d9SStefan Hajnoczi     }
1125419b19d9SStefan Hajnoczi 
1126419b19d9SStefan Hajnoczi     new_l1_size = size_to_l1(s, offset);
1127419b19d9SStefan Hajnoczi     ret = qcow2_grow_l1_table(bs, new_l1_size);
1128419b19d9SStefan Hajnoczi     if (ret < 0) {
1129419b19d9SStefan Hajnoczi         return ret;
1130419b19d9SStefan Hajnoczi     }
1131419b19d9SStefan Hajnoczi 
1132419b19d9SStefan Hajnoczi     /* write updated header.size */
1133419b19d9SStefan Hajnoczi     offset = cpu_to_be64(offset);
1134419b19d9SStefan Hajnoczi     ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, size),
1135419b19d9SStefan Hajnoczi                       &offset, sizeof(uint64_t));
1136419b19d9SStefan Hajnoczi     if (ret < 0) {
1137419b19d9SStefan Hajnoczi         return ret;
1138419b19d9SStefan Hajnoczi     }
1139419b19d9SStefan Hajnoczi 
1140419b19d9SStefan Hajnoczi     s->l1_vm_state_index = new_l1_size;
1141419b19d9SStefan Hajnoczi     return 0;
1142419b19d9SStefan Hajnoczi }
1143419b19d9SStefan Hajnoczi 
114420d97356SBlue Swirl /* XXX: put compressed sectors first, then all the cluster aligned
114520d97356SBlue Swirl    tables to avoid losing bytes in alignment */
114620d97356SBlue Swirl static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
114720d97356SBlue Swirl                                  const uint8_t *buf, int nb_sectors)
114820d97356SBlue Swirl {
114920d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
115020d97356SBlue Swirl     z_stream strm;
115120d97356SBlue Swirl     int ret, out_len;
115220d97356SBlue Swirl     uint8_t *out_buf;
115320d97356SBlue Swirl     uint64_t cluster_offset;
115420d97356SBlue Swirl 
115520d97356SBlue Swirl     if (nb_sectors == 0) {
115620d97356SBlue Swirl         /* align end of file to a sector boundary to ease reading with
115720d97356SBlue Swirl            sector based I/Os */
115866f82ceeSKevin Wolf         cluster_offset = bdrv_getlength(bs->file);
115920d97356SBlue Swirl         cluster_offset = (cluster_offset + 511) & ~511;
116066f82ceeSKevin Wolf         bdrv_truncate(bs->file, cluster_offset);
116120d97356SBlue Swirl         return 0;
116220d97356SBlue Swirl     }
116320d97356SBlue Swirl 
116420d97356SBlue Swirl     if (nb_sectors != s->cluster_sectors)
116520d97356SBlue Swirl         return -EINVAL;
116620d97356SBlue Swirl 
116720d97356SBlue Swirl     out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
116820d97356SBlue Swirl 
116920d97356SBlue Swirl     /* best compression, small window, no zlib header */
117020d97356SBlue Swirl     memset(&strm, 0, sizeof(strm));
117120d97356SBlue Swirl     ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
117220d97356SBlue Swirl                        Z_DEFLATED, -12,
117320d97356SBlue Swirl                        9, Z_DEFAULT_STRATEGY);
117420d97356SBlue Swirl     if (ret != 0) {
117520d97356SBlue Swirl         qemu_free(out_buf);
117620d97356SBlue Swirl         return -1;
117720d97356SBlue Swirl     }
117820d97356SBlue Swirl 
117920d97356SBlue Swirl     strm.avail_in = s->cluster_size;
118020d97356SBlue Swirl     strm.next_in = (uint8_t *)buf;
118120d97356SBlue Swirl     strm.avail_out = s->cluster_size;
118220d97356SBlue Swirl     strm.next_out = out_buf;
118320d97356SBlue Swirl 
118420d97356SBlue Swirl     ret = deflate(&strm, Z_FINISH);
118520d97356SBlue Swirl     if (ret != Z_STREAM_END && ret != Z_OK) {
118620d97356SBlue Swirl         qemu_free(out_buf);
118720d97356SBlue Swirl         deflateEnd(&strm);
118820d97356SBlue Swirl         return -1;
118920d97356SBlue Swirl     }
119020d97356SBlue Swirl     out_len = strm.next_out - out_buf;
119120d97356SBlue Swirl 
119220d97356SBlue Swirl     deflateEnd(&strm);
119320d97356SBlue Swirl 
119420d97356SBlue Swirl     if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
119520d97356SBlue Swirl         /* could not compress: write normal cluster */
119620d97356SBlue Swirl         bdrv_write(bs, sector_num, buf, s->cluster_sectors);
119720d97356SBlue Swirl     } else {
119820d97356SBlue Swirl         cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
119920d97356SBlue Swirl             sector_num << 9, out_len);
120020d97356SBlue Swirl         if (!cluster_offset)
120120d97356SBlue Swirl             return -1;
120220d97356SBlue Swirl         cluster_offset &= s->cluster_offset_mask;
120366f82ceeSKevin Wolf         BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
120466f82ceeSKevin Wolf         if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
120520d97356SBlue Swirl             qemu_free(out_buf);
120620d97356SBlue Swirl             return -1;
120720d97356SBlue Swirl         }
120820d97356SBlue Swirl     }
120920d97356SBlue Swirl 
121020d97356SBlue Swirl     qemu_free(out_buf);
121120d97356SBlue Swirl     return 0;
121220d97356SBlue Swirl }
121320d97356SBlue Swirl 
121420d97356SBlue Swirl static void qcow_flush(BlockDriverState *bs)
121520d97356SBlue Swirl {
121666f82ceeSKevin Wolf     bdrv_flush(bs->file);
121720d97356SBlue Swirl }
121820d97356SBlue Swirl 
121920d97356SBlue Swirl static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
122020d97356SBlue Swirl          BlockDriverCompletionFunc *cb, void *opaque)
122120d97356SBlue Swirl {
122266f82ceeSKevin Wolf     return bdrv_aio_flush(bs->file, cb, opaque);
122320d97356SBlue Swirl }
122420d97356SBlue Swirl 
122520d97356SBlue Swirl static int64_t qcow_vm_state_offset(BDRVQcowState *s)
122620d97356SBlue Swirl {
122720d97356SBlue Swirl 	return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
122820d97356SBlue Swirl }
122920d97356SBlue Swirl 
123020d97356SBlue Swirl static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
123120d97356SBlue Swirl {
123220d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
123320d97356SBlue Swirl     bdi->cluster_size = s->cluster_size;
123420d97356SBlue Swirl     bdi->vm_state_offset = qcow_vm_state_offset(s);
123520d97356SBlue Swirl     return 0;
123620d97356SBlue Swirl }
123720d97356SBlue Swirl 
123820d97356SBlue Swirl 
123920d97356SBlue Swirl static int qcow_check(BlockDriverState *bs)
124020d97356SBlue Swirl {
124120d97356SBlue Swirl     return qcow2_check_refcounts(bs);
124220d97356SBlue Swirl }
124320d97356SBlue Swirl 
124420d97356SBlue Swirl #if 0
124520d97356SBlue Swirl static void dump_refcounts(BlockDriverState *bs)
124620d97356SBlue Swirl {
124720d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
124820d97356SBlue Swirl     int64_t nb_clusters, k, k1, size;
124920d97356SBlue Swirl     int refcount;
125020d97356SBlue Swirl 
125166f82ceeSKevin Wolf     size = bdrv_getlength(bs->file);
125220d97356SBlue Swirl     nb_clusters = size_to_clusters(s, size);
125320d97356SBlue Swirl     for(k = 0; k < nb_clusters;) {
125420d97356SBlue Swirl         k1 = k;
125520d97356SBlue Swirl         refcount = get_refcount(bs, k);
125620d97356SBlue Swirl         k++;
125720d97356SBlue Swirl         while (k < nb_clusters && get_refcount(bs, k) == refcount)
125820d97356SBlue Swirl             k++;
12590bfcd599SBlue Swirl         printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount,
12600bfcd599SBlue Swirl                k - k1);
126120d97356SBlue Swirl     }
126220d97356SBlue Swirl }
126320d97356SBlue Swirl #endif
126420d97356SBlue Swirl 
126520d97356SBlue Swirl static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
126620d97356SBlue Swirl                            int64_t pos, int size)
126720d97356SBlue Swirl {
126820d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
126920d97356SBlue Swirl     int growable = bs->growable;
127020d97356SBlue Swirl     int ret;
127120d97356SBlue Swirl 
127266f82ceeSKevin Wolf     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
127320d97356SBlue Swirl     bs->growable = 1;
127420d97356SBlue Swirl     ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
127520d97356SBlue Swirl     bs->growable = growable;
127620d97356SBlue Swirl 
127720d97356SBlue Swirl     return ret;
127820d97356SBlue Swirl }
127920d97356SBlue Swirl 
128020d97356SBlue Swirl static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
128120d97356SBlue Swirl                            int64_t pos, int size)
128220d97356SBlue Swirl {
128320d97356SBlue Swirl     BDRVQcowState *s = bs->opaque;
128420d97356SBlue Swirl     int growable = bs->growable;
128520d97356SBlue Swirl     int ret;
128620d97356SBlue Swirl 
128766f82ceeSKevin Wolf     BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
128820d97356SBlue Swirl     bs->growable = 1;
128920d97356SBlue Swirl     ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
129020d97356SBlue Swirl     bs->growable = growable;
129120d97356SBlue Swirl 
129220d97356SBlue Swirl     return ret;
129320d97356SBlue Swirl }
129420d97356SBlue Swirl 
129520d97356SBlue Swirl static QEMUOptionParameter qcow_create_options[] = {
129620d97356SBlue Swirl     {
129720d97356SBlue Swirl         .name = BLOCK_OPT_SIZE,
129820d97356SBlue Swirl         .type = OPT_SIZE,
129920d97356SBlue Swirl         .help = "Virtual disk size"
130020d97356SBlue Swirl     },
130120d97356SBlue Swirl     {
130220d97356SBlue Swirl         .name = BLOCK_OPT_BACKING_FILE,
130320d97356SBlue Swirl         .type = OPT_STRING,
130420d97356SBlue Swirl         .help = "File name of a base image"
130520d97356SBlue Swirl     },
130620d97356SBlue Swirl     {
130720d97356SBlue Swirl         .name = BLOCK_OPT_BACKING_FMT,
130820d97356SBlue Swirl         .type = OPT_STRING,
130920d97356SBlue Swirl         .help = "Image format of the base image"
131020d97356SBlue Swirl     },
131120d97356SBlue Swirl     {
131220d97356SBlue Swirl         .name = BLOCK_OPT_ENCRYPT,
131320d97356SBlue Swirl         .type = OPT_FLAG,
131420d97356SBlue Swirl         .help = "Encrypt the image"
131520d97356SBlue Swirl     },
131620d97356SBlue Swirl     {
131720d97356SBlue Swirl         .name = BLOCK_OPT_CLUSTER_SIZE,
131820d97356SBlue Swirl         .type = OPT_SIZE,
131920d97356SBlue Swirl         .help = "qcow2 cluster size"
132020d97356SBlue Swirl     },
132120d97356SBlue Swirl     {
132220d97356SBlue Swirl         .name = BLOCK_OPT_PREALLOC,
132320d97356SBlue Swirl         .type = OPT_STRING,
132420d97356SBlue Swirl         .help = "Preallocation mode (allowed values: off, metadata)"
132520d97356SBlue Swirl     },
132620d97356SBlue Swirl     { NULL }
132720d97356SBlue Swirl };
132820d97356SBlue Swirl 
132920d97356SBlue Swirl static BlockDriver bdrv_qcow2 = {
133020d97356SBlue Swirl     .format_name	= "qcow2",
133120d97356SBlue Swirl     .instance_size	= sizeof(BDRVQcowState),
133220d97356SBlue Swirl     .bdrv_probe		= qcow_probe,
133320d97356SBlue Swirl     .bdrv_open		= qcow_open,
133420d97356SBlue Swirl     .bdrv_close		= qcow_close,
133520d97356SBlue Swirl     .bdrv_create	= qcow_create,
133620d97356SBlue Swirl     .bdrv_flush		= qcow_flush,
133720d97356SBlue Swirl     .bdrv_is_allocated	= qcow_is_allocated,
133820d97356SBlue Swirl     .bdrv_set_key	= qcow_set_key,
133920d97356SBlue Swirl     .bdrv_make_empty	= qcow_make_empty,
134020d97356SBlue Swirl 
134120d97356SBlue Swirl     .bdrv_aio_readv	= qcow_aio_readv,
134220d97356SBlue Swirl     .bdrv_aio_writev	= qcow_aio_writev,
134320d97356SBlue Swirl     .bdrv_aio_flush	= qcow_aio_flush,
1344419b19d9SStefan Hajnoczi 
1345419b19d9SStefan Hajnoczi     .bdrv_truncate          = qcow2_truncate,
134620d97356SBlue Swirl     .bdrv_write_compressed  = qcow_write_compressed,
134720d97356SBlue Swirl 
134820d97356SBlue Swirl     .bdrv_snapshot_create   = qcow2_snapshot_create,
134920d97356SBlue Swirl     .bdrv_snapshot_goto     = qcow2_snapshot_goto,
135020d97356SBlue Swirl     .bdrv_snapshot_delete   = qcow2_snapshot_delete,
135120d97356SBlue Swirl     .bdrv_snapshot_list     = qcow2_snapshot_list,
135220d97356SBlue Swirl     .bdrv_get_info	= qcow_get_info,
135320d97356SBlue Swirl 
135420d97356SBlue Swirl     .bdrv_save_vmstate    = qcow_save_vmstate,
135520d97356SBlue Swirl     .bdrv_load_vmstate    = qcow_load_vmstate,
135620d97356SBlue Swirl 
135720d97356SBlue Swirl     .bdrv_change_backing_file   = qcow2_change_backing_file,
135820d97356SBlue Swirl 
135920d97356SBlue Swirl     .create_options = qcow_create_options,
136020d97356SBlue Swirl     .bdrv_check = qcow_check,
136120d97356SBlue Swirl };
136220d97356SBlue Swirl 
13635efa9d5aSAnthony Liguori static void bdrv_qcow2_init(void)
13645efa9d5aSAnthony Liguori {
13655efa9d5aSAnthony Liguori     bdrv_register(&bdrv_qcow2);
13665efa9d5aSAnthony Liguori }
13675efa9d5aSAnthony Liguori 
13685efa9d5aSAnthony Liguori block_init(bdrv_qcow2_init);
1369